I think that's probably my issue with him. The clips I've seen, on longer or harder passes, he looks sloppy, and also like he's throwing his whole body into the throw, where other QBs with "huge" arms don't seem to have to torque as much on those throws.

But, admittedly, what the hell do I know about it?

I don't see anything wrong with using his body to get more power into the throws. An arm thrower is what will get you in trouble.

As long as Geno is using his proper technique he's extremely accurate and he generates plenty of power into his throws. Arm strength is anything BUT an issue with him.

His wide stance in the pocket is a negative IMO. Such as seen in the avatar pic.

The only issues with him at the next level will be the mental part. But that can be said for any rookie.